Author Archive for Nathaniel Mollica

Last stop: Rawaki

Richard Brooks, Lightening Strike Media Productions, Palau

The last island on our tour de PIPA is Rawaki. We arrived at dawn, greeted by thousands of birds.

Rawaki is different from the previous three islands of our trip, as it has no lagoon and no vegetation larger than grass. It also has no rats, ants, or crabs and has thus become host to a thriving bird colony. At all hours of the day there is a cyclone of frigate birds, noddy terns, boobys, and petrels. The island itself is also much smaller than the others, which means it provides less of a lee and so there is nowhere to escape the open-ocean swell.

Our key mission here is to collect several long cores from coral colonies that are hundreds of years old. The dominant reef builder at Rawaki are massive boulder-shaped Porites—the largest we have seen yet on this trip. We plan to take several cores longer than 100 centimeters (three feet) here, long records that will allow us to see back into the past of the reef to before the industrial revolution in order to study long-term trends and changes in coral bleaching and health.

Our work here is hampered by the swell, at the surface and below. We drop in through a 3-meter (9-foot) haze of sediment that has been kicked up by the waves, into the clearer bottom waters and start to core. As we move coral to coral, trying not to be buffeted by the swell, a new challenge presents itself.

Usually when we core, a steady stream of full air cylinders comes from the surface, dropped by a snorkeler who first makes visual contact with a waiting diver on the bottom. However, here we can’t make visual contact through the sediment layer. This is when Eric and his team become invaluable: Jess and Charlie follow our position by watching the bubbles coming from the drill and Eric, a master free diver, drops down to us to deliver full tanks and take back the empties.

Over three dives, we manage to collect two long and eight short cores. All told, the work is difficult but goes quickly and we get back to the boat exhausted, but successful. Next, we travel back to Kanton to pick up our instruments and drop off Burangke.

Recent Posts

PIPA 2018 Mission

WHOI’s Cohen Lab teams up once again with Pangaea Exploration, this time returning to the remote Phoenix Islands Marine Protected Area. The study site is the planet’s largest and deepest World Heritage Site. It’s been three years since a super El Niño wreaked havoc across the Pacific basin, destroying many coral reefs.

Stay informed!

Adventures in Nikumaroro

This adult orca and its calf (not pictured) represent only the second sighting of orcas, and the first of mother and calf, in PIPA, indicating that these may not be random encounters or pass-throughs by wayward animals, but that the waters around the Phoenix Islands are part of the species' global range. (Photo courtesy of the Cohen Lab, Woods Hole Oceanographic Institution)

Yesterday we arrived at Nikumaroro, perhaps the most famous of the Phoenix islands, as it is the supposed final resting place of Amelia Earhart.

Pat Lohmann extracts a segment from the pneumatic underwater drill being used to extract coral cores.

The island came into view at dawn, shrouded in clouds on our first overcast day of the trip. Nikumaroro has much more vegetation than Kanton despite being a smaller atoll—coconut palms and Pisonea form a dense jungle all over the island. We will only have two short days to work here, before we must move on, so we hit the water swimming.

Our main objective here is to reconstruct a history of bleaching on the reef. To do this, we need to collect coral cores from massive, long-lived Porites colonies that have recorded past thermal stress events in their skeleton. But first we need to find them.

On our first work day Pat, Richard, and Mike conducted surveys across the west side of the island and, while doing so, searched for an area of reef that has enough Porites for us to core while I take water samples to understand the reef chemistry. They found a site just off the northwest corner of the island that is suitable, but may be challenging, as the weather has picked up producing a moderate swell.

Today we plan to spend the entire day coring. The corals are deeper than previous locations, which means we will be using our air rapidly and will have to make multiple dives. The swell has not diminished and so we decide to tie extra ropes to nearby reef rocks to give Pat, our driller, extra handholds. This will allow him to drill a straight hole, which is critical to getting the long records we are after. After a quick breakfast, we head out in both tenders: one full of divers, the other full of extra air tanks.

The drilling setup is elegant in its simplicity; we use a pneumatic drill that has been outfitted to connect to a scuba regulator, which we attach to a full scuba tank. The bit is a 3.5-centimeter-diameter concrete coring bit, which we have repurposed for coral. When Pat pulls the trigger, air from the tank spins the drill and drives the bit into the coral skeleton. We break off sections of core at 30-centimeter intervals, after which we insert aluminum extensions into the drill shaft to extend the bit deeper into the colony. Once the core is completely out, we patch the coral colony with carbonate rubble and epoxy to provide a surface for new coral polyps to grow, a process that typically takes less than a year.

Over three hour-long dives we collect 10 cores, the longest of which is over 100 centimeters and records about a century of growth. We also take tissue samples to analyze for genetics and feeding habits.

Over the course of the day we were visited by an abundance of reef wildlife including a school of barracuda, several black tipped reef sharks, some overly inquisitive red snapper. At the end of the day while Mike and Eric conducted a plankton tow and they encountered two orcas—an adult and a juvenile. The adult, over 20-feet long, makes them feel very small in their 9-foot tender.

Tomorrow we will land on the island so that our observer, Burangke, can make his assessments of the vegetation and wildlife.

The current map showing the distribution of orcas worldwide may need to be updated to include PIPA. (NOAA Fisheries, Office of Protected Resources)

Recent Posts

PIPA 2018 Mission

WHOI’s Cohen Lab teams up once again with Pangaea Exploration, this time returning to the remote Phoenix Islands Marine Protected Area. The study site is the planet’s largest and deepest World Heritage Site. It’s been three years since a super El Niño wreaked havoc across the Pacific basin, destroying many coral reefs.

Stay informed!

Current in Kanton

Richard Brooks, Lightening Strike Media Productions, Palau

It’s our first day at Kanton, and the work started bright and early. Yesterday we anchored just inside Kanton’s 11 kilometer-wide (6 mile) lagoon after motoring in through a narrow channel. This channel is the only major connection that the lagoon has with the open ocean. As the tide goes up, water rushes in, only to course back out when the tide ebbs. One of our key missions here is to study the water entering and exiting the lagoon, and the first thing on our list is to deploy an instrument package right in the middle of this channel.

As our driver, Jess, took us out in one of the tenders, the small engine had to work hard to get back into the channel. With the tide rising, the water was flowing into the lagoon, which made deploying the instrument package a challenge. We rolled into the shallows at the northern edge of the channel and began to move the instruments into place towards the center. The current was ripping and we dropped to the bottom as quickly as possible, so no one would get swept away. Carefully, we edged out to the target and set the package in place.

Although the instruments are housed in a heavy metal frame, we tied it down in both directions (in and out of the lagoon) to make sure the current doesn’t run away with our valuable goods. The process was slow as we fought the current, but we finally finished and scrambled back to the shallows like underwater rock climbers. Despite conditions, the deployment went well and we returned to the ship tired but satisfied.

After lunch, the team headed into the lagoon to do some less intensive, but astoundingly beautiful benthic surveys. We arrived at a patch reef called Coral Castles, known for its massive table Acropora, which fan out in large canopies and provide homes for juvenile fish and invertebrates. In the calm lagoon waters these corals form massive towers, high enough that the tops are exposed at low tide.

Our surveys will determine how this community has fared since the 2015 El Niño and how much it has changed over the last 16 years. We will add to this information tomorrow by collecting skeletal cores from massive, long-lived Porites colonies. The skeletal growth characteristics and geochemistry we get will help us investigate changes in colony feeding habits and growth during El Niño.

Recent Posts

PIPA 2018 Mission

WHOI’s Cohen Lab teams up once again with Pangaea Exploration, this time returning to the remote Phoenix Islands Marine Protected Area. The study site is the planet’s largest and deepest World Heritage Site. It’s been three years since a super El Niño wreaked havoc across the Pacific basin, destroying many coral reefs.

Stay informed!

From Polliwogs to Shellbacks

Richard Brooks, Lightening Strike Media Productions, Palau

Today reached the equator, and the science began.

As the trade winds push water west across the Pacific, the movement is balanced by a deeper counter-flow back to the east known as the Equatorial Under-Current (EUC). The current is narrow and deep—it spans just 2 degrees of latitude on either side of the equator and flows 50 to 200 meters (125 to 500 feet) below the surface. The EUC is cold and nutrient-rich and we are attempting to capture samples to measure the chemistry of its waters.

Where islands like Jarvis break its flow, these cold waters well up, bringing the nutrients the carry to the surface. For reefs like the one at Jarvis, these nutrients allow the corals to grow and build large amounts of biomass, which is thought to help them survive during the extreme temperatures caused by El Niños in this region.

We stop the boat and gather everyone on board. This operation will require all the crew and science team. Eric will be holding the ship steady at the helm, while first mate Shanley and I prepare the Niskin sample bottle and the 40 pounds of lead weight that will keep the line taught. Deckhands Charlie and Shannon, along with Pat will carefully unspool the line and hold the pivot arm steady to lower the bottle down into the EUC. Deckhand Jess is logging our position and Michael is standing by to take the sample once it comes up. Richard decided the best angle to capture the cast would be from the water, so he jumped in with a snorkel to film.

Our greatest challenge for this operation is the depth. We have 180 meters (460 feet) of line, which should get the bottle deep enough to reach the current, but it will be up to the crew to keep the line from swinging out and bringing the bottle too shallow. Lucky for us, they are up to the task; the line remains straight, and we deploy a lead messenger down the line to close the bottle. Once we bring the sample back to the surface, we divide the water inside among separate bottles to be analyzed later for alkalinity, dissolved inorganic carbon (DIC), nutrient concentration, and nitrogen isotope ratios. From this, we can get an idea of the chemistry of the EUC and use the information to isolate the signature of nutrients from the current we may find upwelling at places like Jarvis.

After the initial cast, we take two more at shallower depths and one from the surface. Altogether, the operation takes one and a half hours, even better than we had hoped. Everyone performed admirably and spirits are high as we get back under way. Later, at dinner, Shanley unveils some brownies she baked that are decorated with “polliwogs” turning into “shellbacks”—terms for those who have not crossed the equator and those who have, respectively. They are a delicious alternative to some of the more typical rituals, as we will all be keeping our hair.

Recent Posts

PIPA 2018 Mission

WHOI’s Cohen Lab teams up once again with Pangaea Exploration, this time returning to the remote Phoenix Islands Marine Protected Area. The study site is the planet’s largest and deepest World Heritage Site. It’s been three years since a super El Niño wreaked havoc across the Pacific basin, destroying many coral reefs.

Stay informed!

Starting out on the Sea Dragon

Photo by Richard Brooks

After landing in the small airport in Kiritimati, we loaded our gear onto a truck own by Timei (pronounced “SEE-may” in I’Kiribiati) and drove down the single road looping around the island. The truck rumbled and jerked as we attempt to avoid the large potholes that scar the road as children run along the sides bouncing new tennis balls, gifts from some visiting fishermen.

Kiritimati is the largest atoll in the world, with one massive lagoon and numerous small saltwater ponds surrounded by a semi-circle of land elevated enough to collect a groundwater in a formation called a fresh water lens. These lenses support plant and human life on atolls and are vital to the survival of island nations like Kiribati.

We met up with Eric Loss, the captain of Sea Dragon, who brought us to a pier near their anchorage. From there we scaled down a rickety ladder into one of the two tenders that the ship carries and finally arrived on board. Sea Dragon, once raced as a sailing yacht in the Southern Ocean, is 73 feet long and staffed by a crew of five. While aboard, we will help sail the ship to PIPA. Eric has cleared all the customs hurdles to depart, and after a short visit from a Kiritimati government photographer, we were ready to depart.

As the newest crew members, it was Michael’s and my job to hoist the mainsail that, although easy at first, both of us were straining and sweating as more and more of the sail unfurled. Eric set a course for Kanton, and we departed and, jet-lagged as we are, the watch schedule starts immediately—four hours on, eight hours off. There is a sense of tired excitement among all aboard as we set out for the Phoenix Islands, still six days away.

Recent Posts

PIPA 2018 Mission

WHOI’s Cohen Lab teams up once again with Pangaea Exploration, this time returning to the remote Phoenix Islands Marine Protected Area. The study site is the planet’s largest and deepest World Heritage Site. It’s been three years since a super El Niño wreaked havoc across the Pacific basin, destroying many coral reefs.

Stay informed!

Arrival in Honolulu

Photo by Richard Brooks

Today marks the start of our journey. We met up from disparate places in Honolulu last night to catch the once-a-week flight to Kiritimati (Christmas) Island, 1,200 miles due south of here. This morning we meet over coffee to review the expedition plans. Everyone is eager to get underway.

But…not so fast! We just learned our flight from Honolulu to Kiritimati is delayed 16 hours. So we settle in and wait. It’s aggravating but such is fieldwork! Fortunately, our captain, Eric Loss, already waiting for us in Kiritimati, can use the extra time to clear the strict customs and inspection procedures needed before our vessel Sea Dragon can enter the protected Phoenix Islands.

The sailing vessel must be de-ratted and inspected for insects and other potentially invasive species. There is much concern about Yellow Crazy Ants boarding Sea Dragon in Kiritimati for a free ride to the PIPA! For islands as small as those we’re visiting, even a few stray ants or seeds from a foreign plant can be catastrophic to the entire ecosystem. Rats introduced in 2001 had devastating impact on the island bird populations but thanks to much hard work over several years were successfully eradicated. As visitors to these pristine reefs and islands, it is our responsibility to be good stewards, as well as good scientists.

Recent Posts

PIPA 2018 Mission

WHOI’s Cohen Lab teams up once again with Pangaea Exploration, this time returning to the remote Phoenix Islands Marine Protected Area. The study site is the planet’s largest and deepest World Heritage Site. It’s been three years since a super El Niño wreaked havoc across the Pacific basin, destroying many coral reefs.